Trunking question....Monitoring BOEC from 30+ miles away?

[mh34444]

From south Clackamas County I can pick up the BOEC tower on Goat Mountain with great reception. With only 5 frequencies (1 control channel/1 alternate) I don't seem to be picking up everything going through their system. I could plug the entire system into my scanner and count active frequencies but I would have to do it manually (no frequency counter). Any suggestions or am I geographically challenged?

Also, how exactly do the outlying towers prioritize what they repeat and what they do not? The BOEC backbone has 20 non-control frequencies, mathematically Goat Mountain couldn't possibly handle the entire backbone load.

 

[joescanner]

From south Clackamas County I can pick up the BOEC tower on Goat Mountain with great reception. With only 5 frequencies (1 control channel/1 alternate) I don't seem to be picking up everything going through their system. I could plug the entire system into my scanner and count active frequencies but I would have to do it manually (no frequency counter). Any suggestions or am I geographically challenged?

The Goat Mountain site is a "intellirepeater"; you will only hear traffic that has system users affiliated to that site. You are right, you don't get much listening to Goat. (On a side note, I recommend setting your scanner to "control channel only" as that site has recently had it's frequencies retuned -- and the frequencies you have in your scanner may no longer be correct. The updated frequencies are in the database here.)

Also, how exactly do the outlying towers prioritize what they repeat and what they do not? The BOEC backbone has 20 non-control frequencies, mathematically Goat Mountain couldn't possibly handle the entire backbone load.

The Portland system is a SmartZone system. That means that as radio users move throughout the system's coverage area (it's pretty large), they affiliate to different sites, similar to the way your cellular telephone works (if you have one).

The audio is routed by a device called an Embassy switch, and only traffic necessary to be sent to a particular site is -- the controller keeps track of affiliations to determine where to send the audio.

Almost all traffic (not quite 100%) is funneled through the five-site simulcast system, which has 24 frequencies. You *should* be able to get at least some reception on the simulcast system throughout the tri-county area.

hope that helps,

joe

 

[mh34444]

Update - maybe even a tip for some of you in Clackamas County

I swapped out my all-band antenna to an 800mhz antenna and did some tower specific monitoring of the goat mountain repeater. I'm only receiving 4 talkgroups.

MCSO Dispatch 20816
ODOT Comet Dispatch 17168
Portland Bureau of Water 14544
Portland Bureau of Water Sandy River 13904

This leads me to believe that the system is designed to utilize the goat mountain tower as it's secondary repeater when a user transmits on one of these talkgroups (the primary tower being Walters Hill). Makes perfect sense since all of these talkgroups primarily do "business" in east county. Bureau of water being communications to Bull Run and ODOT communications along I-84 and Hwy 26 (possibly even Hwy 212 and 224).

I would also assume that you would hear fire talkgroup OPS4 (and possibly OPS5) on the goat mountain tower since I know that those talkgroups do in fact hit the Walters Hill tower prior to communicating west.

 

[joescanner]

http://wiki.radioreference.com/index.php/Smartzone

It all depends.

If I take a radio tuned to TriMet Main 1 to a location that receives better coverage from Goat Mountain than elsewhere, you'll start hearing Main 1 from that site. It all depends on which site the radio thinks it is getting the best signal from.

With certain exceptions, you could conceivably hear ALL the talkgroups from Goat Mtn.

It isn't "second" with Walters Hill at all -- they're the same kind of tower.

Any site can carry the radio activity from any talkgroup -- but it requires a radio to be affiliated to the talkgroup at that site before audio gets routed there.

Hope that helps.

 

[scootz]

It all depends. It has to do with the affiliation of the radio to the "best" site. It could be Goat Mtn. or it could be one of the other sites listed in the system. It just depends on which radio site hears the radio best when it affiliates.

A lot of the stuff that you are hearing on Goat Mtn is due to that Tri Met and ODOT both roam in South County and that the Water Bureau also has radios with other agencies along or in Clackamas County may be the reason it comes up on that site.

Usually, those sites are only active when a radio affiliates to that site and then are just in standby mode (control channel is still is active)

Hopes that makes sense.

 

[scootz]

And the Joe beats me to the punch.

And I then totally spaced about the wiki also have good info on it.

I will go back to sleep now.

 

[joescanner]

And the Joe beats me to the punch.

It's called teamwork


joe

 

[DickH]

I would also assume that you would hear fire talkgroup OPS4 (and possibly OPS5) on the goat mountain tower since I know that those talkgroups do in fact hit the Walters Hill tower prior to communicating west.

You might hear OPS4 & OPS5, but there won't be much traffic on them. OPS4 is used only for fires in Gresham. OPS5 is used for fires in Corbett, on Sauvie Island and river incidents.

Dick

 

[mh34444]

You might hear OPS4 & OPS5, but there won't be much traffic on them. OPS4 is used only for fires in Gresham. OPS5 is used for fires in Corbett, on Sauvie Island and river incidents.

I realize that OPS4 is for Gresham fires and OPS5 is for Corbett (as is OPS5 a secondary channel for Gresham), that is why I mentioned them. Geographically speaking, they both would hit the goat mountain tower just as MCSO Dispatch does. OPS4 and OPS5 are designed specifically to ensure that the towers in east county are part of the repeat. It's pretty rare, but if the Walters Hill tower experiences problems (good ol' east county wind or other severe weather), radio coverage is greatly diminished in east county, however, users can transmit just fine from the same location on other talkgroups within the system.

I don't want this to sound like I'm pulling it straight from my rear-end. I've been dispatching for BOEC for 9 years. I honestly don't know why I even have the system tuned into my scanner. Just my sick curiosities I guess. :twisted:

 

[Baker845]

I been meaning to ask if i go out side of Portland such as Mt. Hood or Multnomah falls If i put the intellirepeater control channels for that area would i be able to talk groups for that Intellirepeater.

Thanks

 

[scootz]

Only if a unit/user is affiliated to that site. If no one affiliates to the site, then there will be nothing.

Multnomah Falls you would probaly hear MCSO and possibly fire and Tri-Met, but Mt. Hood you are only probably going to hear CCSO and maybe MCSO.

You are still going to be better off programming the main Smartzone system if you want to hear the majority of the talk groups.

 

[DickH]

Only if a unit/user is affiliated to that site. If no one affiliates to the site, then there will be nothing.

Multnomah Falls you would probaly hear MCSO and possibly fire and Tri-Met, but Mt. Hood you are only probably going to hear CCSO and maybe MCSO.

You are still going to be better off programming the main Smartzone system if you want to hear the majority of the talk groups.

I think he means putting in the rptr site CC in addition to the simulcast site CCs. That should work. Whichever CC is strongest will win.

Dick

 

[joescanner]

Geographically speaking, [OPS4 and OPS5] would hit the goat mountain tower just as MCSO Dispatch does. OPS4 and OPS5 are designed specifically to ensure that the towers in east county are part of the repeat.

When a radio affiliates to a site, the zone controller makes an entry in it''s database that includes the radio number and the talkgroup that is affiliated to it. This information is used to configure the ambassador switch to route audio for that talkgroup to that site. Audio received for that talkgroup is also received by the ambassador switch and routed to all other sites that have a radio affiliated to that talkgroup.

The user of the radio (indeed, not even the dispatchers themselves) has no way of knowing which intellirepeater site they are utilizing when they make their transmissions. Now that the Prune Hill simulcast site is online, a lot of traffic is being taken off of Walter's Hill (except for that which occurs in the shadow of Walter's Hill, presumably).

The point is, the transmission may or may not "geographically hit" the Goat Mountain site, but so long as there is a user that is in the Goat Mtn reception area that has a radio turned on and tuned to that specific talkgroup, you will hear it on the Goat frequencies.

Now. The second piece of this is that certain talkgroups can be configured by the system manager (his last name is Brooks) or infrastructure staff to always send their audio to specific sites regardless of radio affiliation. This may very well be the case as far as OPS4, OPS5 and NET-4 are concerned.

It's pretty rare, but if the Walters Hill tower experiences problems (good ol' east county wind or other severe weather), radio coverage is greatly diminished in east county, however, users can transmit just fine from the same location on other talkgroups within the system.

You've got two different thoughts in this paragraph. As to 'problems' at Walter's Hill, you're right. Radio coverage *could* be greatly diminished. But, due to the expanded coverage of the simulcast system (Prune Hill is online), this is less of a problem.

And, regardless of the problems, with very few exceptions (some of the Airport talkgroups come to mind), any talkgroup can be accessed on every intellirepeater site.

Remember, the simulcast system is now five sites: Lookout Point, Prune Hill, Mt. Scott, Council Crest and Willalatin Tank. If I remember correctly all except Council Crest have omnidirectional antennae, while Crest has directional antennae pointed towards downtown.

I don't want this to sound like I'm pulling it straight from my rear-end.

It sounds like you've got the right concepts. Hopefully the more detailed explanation above will make it more understandable.

SmartZone is a complicated beast. Be thankful that the major comm agencies in the quad-county area haven't decided to OmniLink them. Then it would really be a headache!

Edited to add attachment of Google Earth .kmz file with locations of the Portland Trunked system towers.

 

[Baker845]

Joe thank you for all that info. Also thank you Dick

 

[DickH]

Edited to add attachment of Google Earth .kmz file with locations of the Portland Trunked system towers.[/QUOTE]

What program opens a .KMZ file?

 

[joescanner]

Edited to add attachment of Google Earth .kmz file with locations of the Portland Trunked system towers.

What program opens a .KMZ file?

ummm....

Google Earth .kmz

 

[mikepdx]

disregard this post - by the way, how do I delete a post?

 

[joescanner]

disregard this post - by the way, how do I delete a post?

To ensure integrity of the threads, you can't. However, while you are still in the window where the EDIT key is available you can do what you did. If there is something you really need deleted you can use the "report this post" button on the post, or just pm a moderator.